Resolved questionsHelp with 階

If I'm asking if McDonalds is on the second floor I can say マクドナルドは二階にありますか？However, is there is there a way to simply ask which floor McDonals is on? Is 階 just a counter? Would I just have to say マクドナルドはどこにありますか? Sorry for the long question. ありがとうございます！